Abrading wheels comprising one or more circular abrasive discs are often used to rotatively remove material from a surface. These circular discs are typically die cut from a larger sheet of abrasive material, which may comprise, for example, a backing and a plurality of abrasive grains bonded to the backing. An exemplary circular abrasive disc is available from the Minnesota Mining and Manufacturing Company of St. Paul, Minn. under the designation Three-M-ite.TM. Resin Bond Disc.
In the die cutting process used to produce circular abrasive discs, a plurality of circular dies are arranged to cut a like plurality of discs from the abrasive sheet member. The arrangement of the dies, and thus of the discs cut in the sheet, may be selected as desired. Two such arrangements are shown in FIGS. 1 and 2. The circular abrasive discs are cut from a larger sheet 12 by a die cutting apparatus, leaving a sheet member having a plurality of arranged openings. This operation is known as "converting," and it is desirable in the converting industry to minimize waste when converting large abrasive sheet members into smaller circular abrasive discs. However, some amount of waste is almost unavoidable when cutting circular discs from a rectangular sheet member. This waste, referred to herein as the interstitial sheet material 14, remains between adjacent circular discs after converting, and has heretofore been discarded. This interstitial sheet material can amount to a sizable percentage of the total area of the sheet material, and thus such converting operations can be wasteful and inefficient.
It is therefore desirable to minimize the waste that has previously been the product of abrasive disc converting operations.